Earlier this month, BMW unveiled their latest six-cylinder turbodiesel engine. The said engine has now made its way under the hood of their flagship sedan, the 7 Series. The new quad-turbo diesel replaces the old tri-turbo setup found in the previous generation 7 Series along with the M550d, X550d and X650d.
BMW claims the new range topping diesel 7 Series is more powerful and efficient when compared to the previous generation. The older engine, called the N57S, produced 381 PS and 740 Nm of torque from its 3.0 liter, inline-six mill. Now called the B57, displacement and cylinder count stay the same but it now puts out 400 PS and 760 Nm of torque. 7 Series models equipped with the engine will be called the 750d xDrive and 750Ld xDrive and both models come with an eight speed automatic transmission. As the name suggests, these models will only be available with all-wheel drive.
According to the automaker, power goes up by five percent while efficiency has been improved by eleven percent. BMW credits the improvements thanks to the four turbochargers with a pair of smaller turbines assisting the larger units. Its piezo injectors now come with higher injection pressure, now rated at 2,500 bar to give the fuel system a more even distribution of diesel. It is also equipped with diesel particulate filter and NOX storage catalytic converter, which are positioned in a combined housing close to the engine, as well as a Selective Catalytic Reduction (SCR) system with AdBlue injection.
As for performance, the automaker claims that the F-segment sedan can pull a 0 to 100 km/h run in just 4.6 seconds for the standard wheelbase 750d xDrive. For the long wheelbase 750Ld xDrive, it posted a 0 to 100 km/h time of 4.7 seconds. BMW adds that these times are faster by 0.3 seconds compared to the old tri-turbo engine.
The BMW X5, X6 and upcoming 5 Series will soon be getting the new quad-turbo diesel in the near future.